The present invention relates generally to measuring a stack of coins in a coin handling device.
In the field of coin handling devices, the presence of coins in the device are sensed for a variety of purposes. For example, the number of coins in a coin storage tube can be monitored. Such monitoring allows determinations of the change-making capability of the coin handling device to be made and can be used to determine whether a coin received by the device should be routed to a storage tube or to a cashbox. Thus, when the number of coins in a coin tube becomes too few for change-making purposes, an exact change light can be turned on. When a coin tube becomes full, jamming of the coin path can be reduced by diverting coins directly to the cashbox rather than allowing them to pass to the coin tube.
For some purposes, it is sufficient to provide the coin handling device with the capability of detecting whether the level of coins in each coin tube is below a first low level or above a second high level. The low level can serve to indicate whether the coin tube is substantially empty, whereas the high level can serve to indicate whether the coin tube is substantially full. Various sensors have been devised to detect whether the height of a coin stack in a tube is higher or lower than some discrete level. Such sensors include electromechanical switches, as well as optical or inductive devices. Thus, for example, one sensor can be placed near the top of a coin tube and another sensor can be placed near the bottom of the coin tube.
Although such coin tube sensors can provide an indication of whether the height of a coin stack in a tube has reached one or more discrete levels, they generally are less useful for providing a continuous indication of the actual height of the coin stack or the number of coins. In some applications, however, it is desirable to have a more precise and accurate count of the number of coins in each tube to allow improved auditing and to provide greater flexibility in change-making algorithms.